There have been some known additive methods for fabricating a three-dimensional body, such as optical fabrication. In these methods, as suggested by their name, a three-dimensional body is produced by additively stacking cross-sectional patterns. With no mold or similar equipment required, the three-dimensional body can be fabricated directly from its 3D (design) data. Additive fabrication is thus commonly used in product prototyping, in which it is needed to make a small number of three-dimensional bodies in a short period of time. A typical limitation to additive fabrication is the need for a support. By additive fabrication, in which patterns are built up in layers, it is theoretically impossible to produce a structure that has any portion that would be isolated during the process of fabrication just like, for example, the tip of a drooping branch of a tree. To make such a portion by additive fabrication, it is necessary to provide a support that will not be left in the finished three-dimensional body, or “a prop,” under the portion that would be isolated, and to remove the support after the completion of fabrication.
The removal of the support is basically manual work. As a natural consequence of its purpose, additive fabrication is not often used to mass-produce a single three-dimensional body. There has been no easy and automated way to remove the supports of three-dimensional bodies with different shapes.
As a solution to this, PTL 1 proposes placing a support made from a heat-melting and heat-removable material around a structural body and removing this support through heating after the completion of fabrication. This seems to be a relatively easy way of removing the support.